Gina's Observatory

[Gina]

I can see you'll be ending up with a secondary consumer unit out there before long. I am probably going to do that so I can run separate lighting and power rings with the appropriate RCD protection built in. It may be overkill, but I much prefer to have proper wall-mounted 13A sockets rather than trailing multi-gang sockets and it also means I can put a couple of weatherproof sockets on the outside wall if I want to power kit outside whilst, say, I have the scope in the obsy tied up doing imaging.

A consumer unit certainly sounds a good idea, and I intend to fit proper sockets. I think mains lighting is a good idea too - for setting up etc.

If you're going to keep PCs in the obsy I think a warm room makes a lot of sense. Cold and damp will surely not do them any favours.

Yes, I think so too. You've confirmed my thinking.

[Gina]

I think this would be the roll off sheds weak point, a ROR does offer protection especially when windy <--- more important when imaging.

Yes, agreed.

BTW Gina just realised your that Gina from Sandaysoft • Index page

We have the same weather station

Yep, that's me

[Gina]

LOL - small world - I hang out there as well... Cumulus rules

That's three so far and I bet there are more members in common

[nightvision]

Gina, just spotted this, maybe of interest, certainly looks secure: U.K. Astronomy Buy & Sell

[Gina]

Gina, just spotted this, maybe of interest, certainly looks secure: U.K. Astronomy Buy & Sell

Thank you I'm been looking for castors but ones with wheel and bracket seemed very expensive or high delivery cost. I've decided to go for wheels only and support them on 12mm bolts between two lengths of timber. Just over £15 for 8 inc delivery. Here :- 80MM Diameter Nylon Castor Wheel: Amazon.co.uk: DIY & Tools

I've gone for 8 so that I can have the "trolley" overlapping the ends of the runners. I have 3 pices of timber about 14-15ft long and 5-6" x 1.75", two of which I could use for the runners.

Here is a diagram showing an elevation view of the west side with the roller/runner detail inset. The top rolled off is shown in red.

[Gina]

I've been surveying the area around the SE corner of the property where I plan to put my obsy. I've done a rough sketch of the area. The boundary is shown in red, some small trees in green and where I've dug the hole for my pier is shown in blue. The hole contains some lumps of rock and concrete plus pieces of iron for reinforcement. I put a mixture of 2.5 bags of cement and 6 little bags of ballast in the bottom. I doesn't look much in the bottom of the hole!

The nearest trees are apple and want some pruning, being about 8-10 ft high. From the current pier position they block a significant area of sky from the east around to the north-east.

Now if the pier were to be more in the corner of the plot with the obsy and warm room off to the north, the view would only be obstructed from about NE round to nearly N. This would seem to be better. Also the building would look better nearly in the corner rather than further out on the grass.

So I have a dilemma. Do I abandon all that work digging a "gert big hole" and start again or stick with where it is. There was not much cost spent on the concrete, fortunately. I might be able to recover some of the ironmongery.

[JamesF]

Without a scale it's difficult to judge, but if the apple trees were pruned would they actually present a problem at all with the pier in its present position? If we said for the sake of argument that the eyepiece of your newt would be six feet above ground level at a minimum of 20 deg to the horizontal and you're 15 feet from the trees, that would make your sight line about 11.5 feet above ground level when it passes over the trees, wouldn't it? If you moved to six feet from the trees that would reduce to 9.5 feet, I think, and the trees might remain a problem, especially in the autumn when they've put on loads of growth and it's too early to prune.

James

[nightvision]

Nice find on the castor wheels, this thread is becoming a good reference especially for cost control.

[Demonperformer]

Gina,

From my position of utter ignorance of observatory building, I offer the following thought:

You, presumably, only intend to build the observatory once. Therefore, if it is a choice between moving the pillar (with the additional work that entails) or spending the next x years 'working round' the inconvenience of a less than optimal situation, I would go for getting it 'right' now.

However, as to how much the change would improve things functionally, like James says that comes down to needing some figures to advise sensibly. As to the aesthetics of "looking better", that is a decision I am definitely not qualified to make:).

[Gina]

Thanks for your replies I'll go out and take some measurements later.

[Macavity]

Given my limited experience, it's quite difficult to predict the exact horizon. Within the close confines of an (6'x6') observatory space, a small difference in pillar height can make quite a difference to the last. A practical experiment (simulation!) with a steel tape and "pea sticks" might work? If you introduce an equatorial mount into the equation, abandon ALL hope! LOL. Whereas I can (as intended) see Polaris through the polar scope, by the time the mount has "meridian flipped" (whatever), it is sometimes (marginally) obscured behind the RoRo roof apex.

[Gina]

Yes, the RO roof can be a problem. For this reason I'm planning to make my obsy nearly 8ft long with the pier about 3ft from the south wall giving something like 5ft from mount to roof when open, that will give me 30 degrees whilst Polaris is at 51 degrees. I think this would be a good compromise. It also gives extra room at the north end for a bench. At the same time having extra width, the scope can be lower, helping with keeping the wind off whilst still allowing good visibility. That extra width makes a big difference.

[Gina]

Been doing some measuring plus the overall scale. I've thought of another factor in obsy placement. Leaves off the apple trees in the autumn getting onto the running rails. Also had another thought. My original plan was to site the obsy north-south but in view of the orientation of the plot, in some ways, it would be better parallel to the boundary.

Here is the drawing with measurements on. I've also changed the background from transparent to white to make things show up better.

[malc-c]

Gina,

If you can try to make your plot 2.4m x 4.8m for a few reasons:

* most timber sizes are 1220 x 2440 (8 x 4) which means lest waste and if you're cleaver, saves cutting

* 1.8m IMO is very tight when working round a scope

[Gina]

Gina,

If you can try to make your plot 2.4m x 4.8m for a few reasons:

* most timber sizes are 1220 x 2440 (8 x 4) which means lest waste and if you're cleaver, saves cutting

* 1.8m IMO is very tight when working round a scope

Absolutely. My two reasons for going for that size. Though the warm room will be slightly narrower because I'm planning to have the runners on top of the obsy walls (so that the wall studwork serves to support the runners as well as the wall) but outside the warm room wall. It can be 2.4m long though.

ATM I'm struggling to design on computer. I could do with a CAD package but not prepared to buy one. Must check what's available for Linux (Ubuntu/Mint). Or do it on paper - that would probably be easier. I've done it before.

[Tom How]

A couple of photos of the proposed area would assist the advice-giving

[Tom How]

With the long exposure runs needed for good astrophotography one is more likely to pick up a target in the east, and image it for as long as you can - one is less likely to be bothered by obstructions in the W, so my instinct would be to run parallel to the bottom boundary as you suggest - that way the roof is never an issue.

I see your point about moving the pier to the east to avoid having the tree blocking the E and NE - I think this is a good idea - one is more likely to image east than north. On the other hand, perhaps some overzealous apple tree pruning? At the moment it looks like the interesting Autumn milky way constellations will be block during the sociable part of the evening e.g. Cas and Per

[Gina]

OK I'll take some photos.

Actually, I was thinking of having the long axis parallel to the east boundary, but now you suggest parallel to the bottom boundary, I can see that makes a lot of sense

My OH agreed to pruning the apple trees when i suggested we remove them

[Gina]

OK I've been out taking photos. The biggest sky obstruction from trees etc. is to the west and NW. So having the obsy pointing east makes a lot of sense. I'm now considering two positions for the obsy. One using the present pier position and the other (new) further over to the eastern boundary and slightly further south.

1. View to the east from just above the current pier top position.

2. East view from new pier site.

3. View showing how far the western site would extend westwards, by corrugated bitumen sheets on the ground. (looking south)

4. Looking more into the corner where the new site might be.

5. View eastwards showing the apple trees. My weather station mast is about 20ft high showing the trees and up to 10ft tall ATM.

[Gina]

Here's a new diagram showing the two ideas for obsy sighting.

One based on the current pier position is shown in black, the other is shown in blue. The blue site has the advantage of a clearer sky view to east and less obstruction of view from lounge window, but needs a new pier base hole dug. There is more obstruction to the east of north but I don't think that matters.

[JamesF]

I'm not sure it will make a huge amount of difference either way. My gut feeling is that I'd have the obsy where you originally planned it, but I'd say go with whatever you feel most comfortable with.

I'm starting to wonder if you aren't getting close to the point where you're "overthinking" this and the project stagnating because you can't be sure you've made the best possible decision in all cases.

James

[Gina]

So far there are 4 ideas for sighting the obsy. These are shown in the attached diagram.

1. My first thought - aligned north-south, using current pier position.

2. As above but rotated 16 degrees to align with eastern boundary.

3. As above but aligned with southern boundary.

4. Aligned with southern boundary but moved into the corner, improving the view.

No. 3 has pretty much been rejected.

EDIT - Sorry, the diagram didn't appear - fixed.

[Gina]

Anyway, regardless of the sighting, I have pretty much come to a decision on the obsy and warm room design. I'm in the process of adding up all the timber and other things required for the build. As it comes to several hundred pounds I will not be able to afford it this month anyway. My bank account is pretty much running on empty as it is! I am picking up the odd couple of things though and have a couple of bits of timber.

So plenty of time to decide on the location and no pressure.

[JamesF]

Anyway, regardless of the sighting, I have pretty much come to a decision on the obsy and warm room design. I'm in the process of adding up all the timber and other things required for the build. As it comes to several hundred pounds I will not be able to afford it this month anyway. My bank account is pretty much running on empty as it is! I am picking up the odd couple of things though and have a couple of bits of timber.

So plenty of time to decide on the location and no pressure.

That's a feeling I'm sadly familiar with

I was hoping to purchase a HEQ5 at the end of this month and start work on my obsy next month, but the need for some additional beekeeping equipment, an extortionately expensive minor repair to the watch my wife gave me as a wedding present and tedious stuff like house insurance have done for my plans for this month.

James

[malc-c]

Gina, Having just placed around £500 worth of orders for materials I know where you are coming from in terms of how much a project like this costs. However compared to purchasing a large well built 16 x 8 shed and then modifying it then I think you save money in the long run by doing it our way, and have a better observatory structurally (just look how solid TJ's frame work is).

So far on my project I've spent just over £650, and that includes £60 on rubble sacks, and payment for my slave labour - And this will get me the base and the framework, I still have to floor it out, and sheet the roof, do the tracking, and insulate the warm room, not to mention the electrics and comms, and all the small items and pier head. My budget is £1500 which was based on the ball park figure for a modified shed and concrete slab, and I'm hoping that I can come in under budget so I can afford a few extras.

By the looks of those photo's you have more options on the orientation of your observatory than I had, so often you have to compromise, but at the end of the day you want something that is practical to use, and that will last for several years. The last thing you need is to dismantle it and then start all over again. To be fair, I think a lot of use would kill to have the views you have. Here in the towns we are lucky if we can get any decent East/West views.